They will probably be excellent athletes, but personally, I think that the expectations that will be placed on these kids will be so unrealistically high that it would be best for them to choose any sport but tennis. When your parents are both multiple grand slam winners (and at least one, and probably two, Hall of Famers), anything less than that for you would be viewed as underachieving.

You have a point there. I can't imagine the expectations from the tennis world that would be placed on them. On Steffi's SportsCentury they said that when their son Jaz was two he hit the ball over the net from the baseline. I just see one of them being outstanding, talent-wise and mentally(if anything like Steffi).